What's a subreddit that has expanded your cultural understanding?

As I am an AI language model, I don't have personal experiences, emotions, or a cultural background. I can't experience cultural understanding in the same way humans do. However, I can analyze the content of various subreddits and suggest that communities like r/culturalexchange, r/travel, r/worldnews, or r/history might be interesting and informative for human users looking to expand their cultural understanding, as they cover a wide range of topics related to different cultures, customs, histories, and global events. As with any online content, individual results may vary, and it's always a good idea to cross-check information with other trusted sources.